Press feed control

ABSTRACT

A press feed control comprising a pair of interconnected hydraulic cylinders, a piston in one cylinder mechanically operated by press actuation to displace fluid which in turn displaces the piston in the timing cylinder, which piston is connected to feed mechanism. Resilient means urge the feed mechanism in the direction tending to move the piston in the timing cylinder to return fluid to the first cylinder. A check valve and an adjustable metering valve are provided in the connection between the cylinders.

United States Patent [72] Inventor Joseph W. Baldyga Utica, Mich. [21] Appl. No. 855,847 [22] Filed Sept. 8, 1969 [45] Patented May 11, 1971 [73] Assignee Diamond Die 81 Mold Co.

Mt. Clemens, Mich.

[54] PRESS FEED CONTROL 11 Claims, 7 Drawing Figs.

[52] US. Cl .1 226/ 162, 72/421, 83/223, 100/215 [51] Int. Cl B65h 17/04 [50] Field of Search 226/150, 162; 72/421, 424; 83/223; 100/215 [56] References Cited UNIT ED STATES PATENTS 2,467,740 4/1949 Haller 226/ 162X v 1 l l2\ l8\ I, V: ?a IO \N i 2,634,974 4/1953 Chuy 226/ 162 2,863,659 12/ 1958 Chuy 226/150 2,963,931 12/ 1960 Lamoureux 83/223 3,038,645 6/ 1962 Nordlof 226/162X 3,125,270 3/1964 Ronfeldt... 226/150X 3,390,567 7/1968 Frastaci 72/421 Primary Examiner-Billy J. Wilhite Attomey-Whittemore, Hulbert & Belknap ABSTRACT: A press feed control comprising a pair of interconnected hydraulic cylinders, a piston in one cylinder mechanically operated by press actuation to displace fluid which in turn displaces the piston in the timing cylinder, which piston is connected to feed mechanism. Resilient means urge the feed mechanism in the direction tending to move the piston in the timing cylinder to return fluid to the first cylinder. A check valve and an adjustable metering valve are provided in the connection between the cylinders.

Patented May 11,' 1971 3 Sheets-Sheet 1 .INVENTOR. BALDYGA ATTORNE S Patented May 11,1971 3,578,230

3 Sheets-Sheet 5 s| 90 as 84 88 92 FlG.6

FIG?

INVENTOR. JOSEP)-I7W. BALDYGA ATTORNEYS PRESS FEED CONTROL BRIEF SUMMARY OF THE INVENTION- In automatic press operation the timing of the feed intermediate press strokes is sometimes troublesome. In high speed operation it is desirable to take advantage of the full interval available between die strokes and further, to provide a control of the feeding stroke independent of the stroke of the press ram.

In accordance with the present invention, ram movement and particularly, the latter portion of the working stroke, is used to operate a piston to displace hydraulic fluid from a first cylinder past a check valve into a timing cylinder, where it displaces a piston connected to feeding mechanism. The timing cylinder may conveniently be of relatively small cross section and elongated to provide a stroke equal to the required stroke of the feeding mechanism or feeder-actuator mechanism.

Movement of the piston in the timing cylinder is opposed by spring means which stores up energy available for carrying out the feeding operation.

Preferably, completion of the down stroke of the press and accordingly, completion of the idle stroke of the piston in the timing mechanism, sets a latch which prevents initiation of feeding movement at this time. Upon upward or return movement of the press ram, adjustable means are provided to release the latch at the desired point in travel of the ram and to permit the spring to operate the feed mechanism. The rate of feeding movement is regulated by an adjustable metering valve provided in the return passage for hydraulic fluid from the timing cylinder to the other cylinder.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an elevational view of the mechanism including the lower portion of the press ram.

FIG. 2 is a plan view of the mechanism seen in FIG. 1.

FIG. 3 is a fragmentary plan view of the feeding mechanism and associated cylinders of a modified construction.

FIG. 4 is an elevational view of the structure shown in FIG. 3.

FIG. 5 is an end view of the structure shown in FIG. 4.

FIG. 6 is a longitudinal enlarged sectional view on the line 6-6, FIG. 3.

FIG. 7 is a diagrammatic view'partly in section, illustrating modulating flow control.

I DETAILED DESCRIPTION slidable. The slide 14 has a die 16 mounted thereon for coaction with an anvil 18 and is adapted to perform an operation on a succession of articles indicated at 20, which articles may be connected by tape or the like.

The slide 14 is provided with a tapped opening 22 for connection to the ram of a press.

The problem which is solved by the present construction is to advance the articles into proper position relative to the anvil l8 and die 16 during the interval between the time the die clears the anvil on its upward stroke and the time when it engages the workpiece for operation thereon in conjunction with the anvil.

In general terms, this operation is carried out by a feed carriage 24 having a pivoted feed'dog 26 thereon engageable to push individual articles or work elements 20 to the left to advance a new element 20 into the working station while the die 16 is removed upwardly therefrom. The dog 26 is pivoted on a post 28 and is biased by a coil spring 30 in a counterclockwise direction as seen in FIG. 1. With this arrangement the dog on its idle or return stroke to the right, slides over a workpiece, but on its return stroke it advances the entire series of workpieces a distance equal to the spacing between adjacent pieces.

The means for effecting movement of the feed slide or carriage 24 comprises a cylinder 32 having a piston 34 therein the upper portion of the piston projecting above the cylinder for engagement with a threaded abutment screw 36 carried by the slide 14.

As will be described in greater detail in conjunction with the embodiment of the invention illustrated in FIGS. 3-6, hydraulic fluid displaced from the cylinder 32 is displaced past a check valve into a timing cylinder 38 having a piston therein connected to a piston rod 40 which connects to the feed slide 24. Movement of the feed slide 24 to the right as hydraulic fluid is displaced into the cylinder 38, tensions feed springs 42. At the same time the feed slide 24 is latched in its retracted position, or to the right as seen in FIG. I, by a latch arm 44 engaging an abutment 46 on the feed slide. The latch arm 44 is pivoted as indicated at 48 and includes an upwardly extending release arm 50 having a camming surface-52 thereon adapted to be engaged by the camming surface 54 of a release arm 56 adjustably secured to the slide 14 by a clamping screw 58 or the like.

With this arrangement it will be observed that upon initiation of the upward stroke of the slide 14, the latch arm 44 will be swung upwardly, releasing the feed slide 24 for feeding movement to the left under the actuation of the springs 42.

The rate of movement of the feed slide 24 may be controlled by a metering valve as will be apparent from the detailed description of the embodiment of the invention illustrated in FIGS. 46.

Referring now to the construction illustrated in FIGS. 4-6, a cylinder 60 corresponding to the cylinder 32 previously described, is provided in a casting 61 and has a piston 62 therein extending above the upper end of the cylinder and sealed by suitable means such for example as the resilient sealing ring 64. Formed in the same casting in which the cylinder 60 is formed is a second cylinder 66 communicating with the cylinder 60 through a passage 68 controlled by a check valve 70 and a bypass passage 72 controlled by an adjustable needle valve 74. Slidable longitudinally in the cylinder 66 is a piston I 76 having a projecting portion forming a connecting piston rod portion 78 adapted be connected to an arm 80 of the feed slide 81 by a suitable means such as the screw 82. The feed slide 81 also has an upwardly projecting boss 84 which is apertured as indicated at 86 to receive an abutment screw 88 one end of which is threaded into a threaded recess in the casting 61. Adjustment abutment nuts 90 and 92 are provided to limit the stroke of the feed slide 81 as required.

It will be observed that the cylinder 60 is substantially larger in cross section than the cylinder 66 so that a short travel of the piston 62 produces substantially more movement of the piston 76. The amount of movement imparted to the piston 62 by downward movement of the slide, such as the slide 14 connected to the press ram, may be adjusted by means such as the adjustable abutment screw 36 previously described.

Downward movement of the ram produces relatively abrupt movement of the piston 62 and fluid displaced from the cylinder 60 unseats the check valve 70 and moves the piston 76 to the right at a rate faster than the rate of movement of the piston 62. The feed slide 81 is latched to the right by latch mechanism similar to that illustrated in FIGS. 1 and 2.

On the up stroke of the ram and the slide 14 the latch is released and the feed slide 81 moves to the left in a feeding stroke under driving force imparted by the springs illustrated in FIGS. 3 and 4 at 94. Movement of the piston 76 to the left is pennitted only by displacement of hydraulic fluid from the cylinder 66 back into the cylinder 60. Flow of fluid in this direction is prevented by the check valve 70 but is permitted by the metering bypass passage 72 as controlled by the needle valve 74. Accordingly, the rate of movement of the feed slide may be determined by adjustment of the needle valve 74 and the camming surface 52 at the desired point in up stroke of the ram.

While a constant speed feed movement will be provided by adjustment of the needle valve 74, it will be understood that if desired, valve means operable in timed relation to movement of the feed slide to the left on its feeding movement may be provided. With this arrangement the feeding movement may accelerate to a maximum and then decelerate to reduce the feed cycle to a minimum while at the same time avoiding difficulties due to inertia when the articles being feed constitute a substantial mass. Such an arrangement is illustrated in FIG. 7 in which a needle valve 100 restricts and regulates flow through the return passage 102 when the ball check valve 104 prevents return flow through the enlarged passage 106 cor responding to the passage 68 seen in FIG. 6.

Valve 100 is biased toward open position by a spring 108 and its modulating movement is controlled by an elongated cam 100 movable in the direction of the arrow by suitable mechanical connections to the feed slide. lt will be observed that the cam 110 is formed of two sections 112 and 114 which are adjustable longitudinally of each other and which may be secured in adjusted position by suitable clamping means indicated diagrammatically at 116. Each end of the cam 110 includes a rise portion adapted when it engages with the needle valve 100 to restrict flow through the passage 102. By suitably shaping the camming surfaces of the cam, the feed stroke of the slide 81 may be accelerated and decelerated smoothly to provide for maximum velocity of the fed structure without difficulties which might occur due to inertia in starting and stopping a substantial mass of work elements.

While the invention has been illustrated in association with a press in which the press ram is continuously reciprocable, it will be appreciated that the invention is generally applicable to any type of machine tool having a tool slide reciprocable toward and away from a work support. Thus for example, the operation instead of carrying out a stamping operation on the workpieces, could involve the use of a tool which would perform a cutting operation, a staking operation, or any other operation normally provided by movement of the tool slide.

Since the function of the cylinder 32 or 60 is essentially to load the feed slide by moving it against the action of the springs 42 or 94, this cylinder has been referred to as a loading cylinder.

Reference is also made to the fact that the specific disclosure is of an arrangement in which pistons are movable in and extend beyond the ends of cylinders fomied in a block. Obviously, equivalent results could be obtained by imparting movement to cylinders while the pistons remain fixed. Accordingly, the constructions are referred to generically as piston and cylinder devices.

lclaim:

1. Feed mechanism for use with a press, said mechanism comprising a feed slide, a timing piston and cylinder device connected to said feed slide, a loading piston and cylinder device. a fluid passage connecting the cylinders of said devices, a check valve'in said passage adapted to open to permit flow from said loading device to said timing device, a restricted timing passage connecting the cylinders of said devices, resilient means biasing said feed slide for movement in feeding direction, said feed slide being moved in return direction upon displacement of fluid into said timing device, said loading device including a movable part adapted to be engaged by means connected to the ram of the press near the abutment means acting between the press ram and said loadmg device to determine the amount of fluid displaced from said loading to said timing device.

3. Mechanism as defined in claim 1 comprising adjustable restricting means in said restricted timing passage.

4. Mechanism as defined in claim 1 comprising means for adjusting said latch release means to determine the point during return movement of the press ram at which feed movement of said feed slide is initiated.

5. Mechanism as defined in claim 1 in which both of said devices comprise cylinders formed in a single body, pistons in said cylinders, and extensions connected to said pistons extending outwardly beyond the outer ends of said cylinders.

6. Apparatus of the character described comprising a base including work support structure, a tool slide movable on said base toward and away from said work support structure in working and idle return strokes, a feed slide movable on said base in feed and idle return strokes, means for timing operation of said feed slide with movement of said tool slide comprising a loading piston and cylinder device and a timing piston and cylinder device on said base, a loading passage connecting the cylinders of said devices, a check valve in said loading passage to limit fluid flow therethrough to a flow from said loading to said timing device, a restricted timing passage connecting the cylinders of said devices, abutment means on said tool slide engageable with said loading device during the latter portion of the working stroke of said tool slide to effect relative movement between the piston and cylinder portions thereof to displace fluid into the cylinder of said timing device, resilient means connected between said base and said feed slide and biasing said feed slide in its feed stroke, a latch acting between said base and said feed slide and retaining said feed slide in retracted position, and latch release means including a member movable with said tool slide operable to release said latch to initiate feed movement of said feed slide at a selected point in the idle return stroke of said tool slide.

7. Apparatus as defined in claim 6 comprising adjustable abutment means acting between said tool slide and said loading device to determine the amount of fluid displaced from said loading to said timing device.

8. Apparatus as defined in claim 6 comprising adjustable restricting means in said restricted timing passage.

9. Apparatus as defined in claim 6 comprising means for adjusting said latch release means to determine the point during return movement of the work slide at which feed movement of 

2. Mechanism as defined in claim 1 comprising adjustable abutment means acting between the press ram and said loading device to determine the amount of fluid displaced from said loading to said timing device.
 3. Mechanism as defined in claim 1 comprising adjustable restricting means in said restricted timing passage.
 4. Mechanism as defined in claim 1 comprising means for adjusting said latch release means to determine the point during return movement of the press ram at which feed movement of said feed slide is initiated.
 5. Mechanism as defined in claim 1 in which both of said devices comprise cylinders formed in a single body, pistons in said cylinders, and extensions connected to said pistons extending outwardly beyond the outer ends of said cylinders.
 6. Apparatus of the character described comprising a base including work support structure, a tool slide movable on said base toward and away from said work support structure in working and idle return strokes, a feed slide movable on said base in feed and idle return strokes, means for timing operation of said feed slide with movement of said tool slide comprising a loading piston and cylinder device and a timing piston and cylinder device on said base, a loading passage connecting the cylinders of said devices, a check valve in said loading passage to limit fluid flow therethrough to a flow from said loading to said timing device, a restricted timing passage connecting the cylinders of said devices, abutment means on said tool slide engageable with said loading device during the latter portion of the working stroke of said tool slide to effect relative movement between the piston and cylinder portions thereof to displace fluid into the cylinder of said timing device, resilient means connected between said base and said feed slide and biasing said feed slide in its feed stroke, a latch acting between said base and said feed slide and retaining said feed slide in retracted position, and latch release means including a member movable with said tool slide operable to release said latch to initiate feed movement of said feed slide at a selected point in the idle return stroke of said tool slide.
 7. Apparatus as defined in claim 6 comprising adjustable abutment means acting between said tool slide and said loading device to determine the amount of fluid displaced from said loading to said timing device.
 8. Apparatus as defined in claim 6 comprising adjustable restricting means in said restricted timing passage.
 9. Apparatus as defined in claim 6 comprising means for adjusting said latch release means to determine the point during return movement of the work slide at which feed movement of said feed slide in initiated.
 10. Apparatus as defined in claim 6, the cylinder of said loading device having a cross-sectional area much greater than that of said timing device.
 11. ApparatUs as defined in claim 6 comprising variable restriction valve means in said timing passage, and means operatively connected to said feed slide to variably restrict the passage in accordance with movement of the feed slide. 